At the time of holding events such as various games, entertainments, and recreations, to produce fun of encounter and participation in a group, in many cases, a group participating method of dividing event participants into groups of predetermined number of people is often employed. The grouping of participants is generally performed in advance by an organizer at random or according to attributes of the participants and the like (refer to, for example, patent document 1).
Whether participants grouped and gathered are in the same place at the same time or not is confirmed by using GPS locator-equipped mobile terminals carried by the participants (refer to, for example, patent document 2).
Patent document 1: Japanese Patent Application Laid-Open (JP-A) No. 2004-171239
Patent document 2: JP-A No. 2000-331284